M16CSLASH26 datasheet(226/239 Pages) RENESAS

226 / 239 page

Renesas Technology Corp.

Appendix Standard Serial I/O Mode 2 (Flash Memory Version)

220

M16C/26 Group

SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Under

development

Preliminary Specifications Rev. 0.9

Specifications in this manual are tentative and subject to change.

Appendix Standard Serial I/O Mode 2 (Flash Memory Version)

Overview of standard serial I/O mode 2 (clock asynchronized)

In standard serial I/O mode 2, software commands, addresses and data are input and output between the

microcomputer and peripheral units (serial programer, etc.) using 2-wire clock-asynchronized serial I/O

(UART1). Standard serial I/O mode 2 is engaged by releasing the reset with the P65 (CLK1) pin “L” level

and P86 (CE) pin and the CNVss pin are in “H” level).

The TxD1 pin is for CMOS output. Data transfer is in 8-bit units with LSB first, 1 stop bit and parity OFF.

After the reset is released, connections can be established at 9,600 bps when initial communications

(Figure 1.23.1) are made with a peripheral unit that requires a main clock with a minimum 2 MHz input

oscillation frequency. Baud rate can also be changed from 9,600 bps to 19,200, 38,400 or 57,600 bps by

executing software commands. However, if communication errors due to the oscillation frequency of the

main clock, change the main clock's oscillation frequency and the baud rate.

After executing commands from a peripheral unit that requires time, i.e. erase, or write (program) data,

allow sufficient time to pass or execute the read status command to check the device status, before execut-

ing the next command.

Data and status registers in memory can be read after transmitting software commands. Status, such as

the operating state of the flash memory or whether a program or erase operation ended successfully or not,

can be checked by reading the status register. The following describes the initial communications with

peripheral units, how frequency is identified, and software commands.

Initial communications with peripheral units

After the reset is released, the bit rate generator is adjusted to 9,600 bps to match the oscillation fre-

quency of the main clock, by sending the code as prescribed by the protocol for initial communications

with peripheral units (Figure 1.23.1).

(1) Transmit “B016” from a peripheral unit. If the oscillation frequency input by the main clock is 10 or 16

MHz, the microcomputer with internal flash memory outputs the “B016” check code. If the oscillation

frequency is anything other than 10 or 16 MHz, the microcomputer does not output anything.

(2) Transmit “0016” from a peripheral unit 16 times. (The microcomputer with internal flash memory sets the

bit rate generator so that “0016” can be successfully received.)

(3) The microcomputer with internal flash memory outputs the “B016” check code and initial communica-

tions end successfully *1. Initial communications must be transmitted at a speed of 9,600 bps and a

transfer interval of a minimum 15 ms. Also, the baud rate at the end of initial communications is 9,600

bps.

*1. If the peripheral unit cannot receive “B016” successfully, change the oscillation frequency of the main clock.

Figure 1.23.1. Peripheral unit and initial communication

Microcomputer with

internal flash memory

Peripheral unit

(1) Transfer "B016"

If the oscillation frequency input

by the main clock is 10 or 16 MHz,

the microcomputer outputs "B016".

If other than 10 or 16 MHz, the

microcomputer does not output

anything.

(2) Transfer "0016" 16 times

At least 15ms

transfer interval

1st

2nd

15 th

16th

(3) Transfer check code "B016"

"B016"

"0016"

"B016"

"0016"

Reset

The bit rate generator setting completes (9600bps)

M16C/26 датащи(PDF) 226 Page - Renesas Technology Corp

M16C/26 датащи(HTML) 226 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL